Today's golfers are constantly seeking means for improving their game. One avenue for improvement that golfers are turning to is the adjustable, or customizable, golf club. Previously, the United States Golf Association (USGA) rules permitted golf clubs to be adjustable only with respect to the weight of the golf club. However, since 2008, the USGA has allowed golf clubs to be designed with adjustable features other than weight, such as lie, face angle, and/or length. As a result, golfers now have a number of options for customizing a golf club to fit their particular preferences.
One particular aspect of the game where many golfers seek improvement is gapping, a term used to difference in distance obtained by one club to the next club in the set. In convention iron sets, such as traditional forged or cast cavity back irons, the gapping between clubs has traditionally been relatively uniform. However today with the introduction of hybrids and trans-hybrids, or hollow-irons, into traditional iron sets the gapping between clubs has become more of a concern. Particularly since such hybrids and trans-hybrids are incorporating new technologies that increase the distances associated with these clubs. Integrating such clubs into a set introduces new challenges in obtaining preferred gapping.